Thank you, guys!
I really appreciate your help.
Too bad SWIM has nothing to report thus far. Here's what happened; maybee someone who's had experience w/this rxn (Placebo?) can give him an advice.
A 250 ml flask was equipped w/a thermometer & a air condenser (well, sort of - a 25cm x 1cm tube). A hose leading to outside of the apartment was attached to the condenser as not to accidentally blow the place apart
55mls BDO + 4g catalyst.
(Guess the making of it is the most important part, but SWIM's followed Placebo's directions as close as possible, care being taken as not to contaminate the catalyst w/SO
42- and Cl
- at all times).
Heated on a gas stove (metallic net interposed above the flame).
Dehydrogenation started at ~175 C! Yes!
Tiny fine bubbles, which definitely created pressure (H2 evolution was tested by briefly plugging the out-hose w/SWIM's tongue).
Heating was cont'd for 4 hrs - the temp gradually rose to 210 C (it seemed that in the beginning, increasing the heat just led to more H2 effervescence, but not to temp. increase! SWIM's not 100% positive about that, though.)
Some liquid was definitely boiling/refluxing inside the flask at the time (i assume, GBL). Also there was noted a specific, very unpleasant smell (SWIM's never tasted/smelled GBL (nor has he ever had GHB, for that matter)) - it was completely unlike 'gasoline', rather like.... Well, i'm not sure. Somewhat similar to spoiled butter (is that GBL or some imputity? Help!). The taste of the insides was bitter (however, some BDO'ic taste was also present).
Another thing SWIM noted is that the catalyst changed in appearance from utterly black to sorta brownish, just a lil' bit. To check if it's lost activity, some more catalyst was added and it did NOT lead to any more H2 evolution. Some 4mls BDO was added and it DID lead to more H2 evolution. The mixtr was heated for further 2hrs.
When it was cooled and measured, it amounted to only 40mls! (WTF? Where did the rest go? Got carried away w/hydrogen? Definitely it wasn't boiled off as the 'condenser' held the temperature well - still, i guess, will have to try a water condenser the next time. What will the experienced ones say on this matter?)
So. As you can see, thus far all looked well. Now i'll get to the part where the problems beegan.
SWIM decided that he wasn't going to distill the stuff but rather cheat a little
(YES! This is the phrase with which all failure reports are usually beegun! )He thought he'd just dump in some water/baking soda, reflux it till complete convertion to NaGHB (30mins, according to Chromic!), THEN filter (the viscous mixture w/the fine, fine Cu-chromite powder was definitely unfilterable), xtract the unreacted BDO w/some CHCl3 and, - eh - like, voila
.
An idiot! Yes
. He could've at least 1st dilute the mixtr w/water and THEN filter it.
Anyway. He didn't have any soda in the house
so he added K2CO3 instead. And boiled the mixtr for about 2 hours. The smell didn't disappear. The catalyst changed in appearance to brown and its consistency beecame fluffy and very filterable. Definitely reacted. An aliquot was taken and xtracted w/chloroform - upon evaporation it yielded some bitter liquid w/that characteristic unpleasant smell and taste completely unlike that of BDO. The liquid itself was brown and muddy.
WTF! If it was GBL, then it DIDN'T hydrolyze w/K2CO3 in 2 hours!
A sample of the liquid was active in a not-unpleasant way, different from BDO - but of course SWIM wasn't going to use it as is. (Ewwww).
Then it was boiled for yet further 2hrs, xtracted w/chloroform (didn't get rid of the yellow coloration!), most water evap'd, the mess xtracted w/EtOH, alcohol evaporated to leave a brown slurry that was completely inactive
.
So. Of course, you're gonna tell me, the best way would bee to distill the mixture and then work-up the distillate. Alright. But still, here are some questions which i would very dearly like to have your opinion about:
- what if SWIM diluted the rxn w/water, filtered and then hydrolysed? Anyone had such an experience?
- HOW LONG does it take for a conc. NaOH solution to quantitatively hydrolyse GBL?
- Can someone describe in detail (yes, i've read all the previous descriptions, but still) how GBL should smell and taste?Placebo, i am especially interested in your experience with this reaction, you must've had quite a bit of it - and, BTW, i am
profusely grateful to you for your work and inspiration! I am truly honoured to at last make acquaitance with you on this board
Antoncho